One-Hit Wonders

• 
• 16%
• have only posted one review

101 of the 631 reviewers have only reviewed this product. While this is more One-Hit Wonders than we'd expect to see, it does not appear to have a significant impact on the overall rating.

Take-Back Reviewers

• 
• 19%
• have previously deleted reviews

123 of the 631 reviewers have had at least one of their past reviews for another product deleted. This is an excessively large percentage of Take-Back Reviewers which may indicate unnatural reviews.

Read more about our Suspicious Reviewers test.

• 
• 26%
• Used substantial repetitive phrases

165 of the 631 total reviews for this product use substantial repetitive phrases between them. These reviewers have rated this product an average of 4.6 while reviews without substantial repetitive phrases rated this product an average of 4.4. Based on our statistical modeling, the discrepancy in average rating between these two groups is significant enough to believe that the difference is not due to random chance, and may indicate that there are unnatural reviews.

Read more about our Phrase Repetition test.

• 
• 13%
• Created over 14 days

We counted 631 reviews for this product over the span of 1,751 days, an average of 0.4 reviews per day. If these reviews were created randomly, there would be a 99.9% chance that we would see 4 or fewer reviews on any given day.

However, we see the following 14 days exceeding this threshold:

• 9 Reviews on Oct 22, 2014 (Avg. rating: 4.6)
• 8 Reviews on Nov 12, 2014 (Avg. rating: 4.4)
• 8 Reviews on Oct 12, 2014 (Avg. rating: 3.9)
• 6 Reviews on Oct 29, 2014 (Avg. rating: 4.8)
• 6 Reviews on Oct 27, 2014 (Avg. rating: 4.2)
• 6 Reviews on Oct 20, 2014 (Avg. rating: 4.0)
• 6 Reviews on Oct 10, 2014 (Avg. rating: 3.8)
• 5 Reviews on Oct 9, 2014 (Avg. rating: 5.0)
• 5 Reviews on Oct 15, 2014 (Avg. rating: 4.8)
• 5 Reviews on Nov 14, 2014 (Avg. rating: 4.4)
• 5 Reviews on Oct 14, 2014 (Avg. rating: 4.2)
• 5 Reviews on Dec 2, 2014 (Avg. rating: 4.2)
• 5 Reviews on Feb 20, 2015 (Avg. rating: 4.2)
• 5 Reviews on Oct 28, 2014 (Avg. rating: 3.6)
Show All

In total, we found that 84 reviews were created on just 14 days. Although any days with a larger number of reviews than expected is suspicious, these reviews do not appear to have a significant impact on the overall rating.

Read more about our Rating Trend test.

• 
• 36%
• Have an overrepresented word count

In the graph above, we can see the distribution of review word counts for this product and the expected distribution for this category. We see the following 1 group with a statistically significant greater concentration than what we'd expect to see:

• 26-40 words: 36.3% (Avg. rating: 4.5)

In total, we found that 229 reviews (or 36%) are within an overrepresented word count group. While this is more reviews from overrepresented word count groups than we'd expect to see, these reviews do not appear to have a significant impact on the overall rating.

Read more about our Word Count Comparison test.

• 
• 17%
• Unverified Purchases

108 of the 631 total reviews for this product are unverified purchases. This is within an acceptable range and it does not appear to be significantly affecting the overall rating for this product.

Unverified purchases may be the result of Kindle Unlimited readers, buyers who didn't pay full price, or reviewers who did not purchase the product at Amazon. Read more about our Unverified Purchases test.

• 
• 16%
• Substantial overlapping review history

102 of the 631 reviewers have substantial overlapping product review history. This is within an acceptable range and it does not appear to be significantly affecting the overall rating for this product.

Read more about our Overlapping Review History test.

• 
• 0%
• From reviewers with an overrepresented participation

We didn't find any participation groups that had a statistically significant greater concentration than what we'd expect to see in this category.
Read more about our Reviewer Participation test.

The ease score is the average rating for all reviews that a given reviewer submits. The average ease score for reviewers of this product is 4.2, while the average ease score for reviewers in this category is 3.9. While this discrepancy is rather large, it is not quite large enough to rule out the possibility of it being due random chance.

Brand Repeaters

We didn't detect a substantial amount of Brand Repeaters.

On Oct 3, 2016, Amazon prohibited incentivized reviews, however we still test for them since there are still millions in our dataset.

• 
• 0%
• Admitted to receiving an incentive

We didn't detect any reviews that used language indicating they were incentivized.
Read more about our Incentivized Reviews test. Check out our study showing that Incentivized Reviewers are much more likely to leave a positive review.

• 0
• Reviews have been deleted

We have not discovered any deleted reviews for this product.

There are a few limitations to keep in mind regarding the Deleted Reviews test:

1. We don't have a magic ability to collect every single deleted review; we can only identify reviews as deleted if we collect them on one date and then notice they are no longer visible on a subsequent date.
2. We have no information on reviews that were never published in the first place.
3. We also don't know why these reviews were removed. It could be action from the platform, personal decision by the review author, part of an entire account closure, even some data error on our part, etc.

Read more about our Deleted Reviews test.